License Explanations

Public Domain

Works in the public domain have no copyright (in most cases because the copyright term has expired) and you are free to use, adapt, share, and distribute the work in any way you wish.

Public Domain (US Only)

Works may be in the public domain in the Unites States (where you can use and distribute them without restriction), but still subject to copyright laws and restrictions outside the United States.

Creative Commons Licenses

Creative Commons licenses allow rights-holders to grant people the right to freely use their creations in certain ways and perhaps by meeting certain requirements. There are several licenses with different combinations of four basic clauses:

BY
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
NC
NonCommercial — You may not use the material for commercial purposes.
ND
NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material.
SA
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.

The following Creative Commons licenses are applied to materials in Digital Research Books Beta. Refer to linked license descriptions for specifics:

CC0 Public Domain Dedication

The CC0 1.0 Universal (CC0 1.0) Public Domain Dedication waives all rights under worldwide copyright law. It allows you to use, adapt, share, and distribute the work as if it were in the Public domain.

GNU General Public License

For a work licensed under the GNU General Public License, you may copy, distribute and modify the work as long as any modifications are also made available under the GPL.